Apparatus and method for retrofitting a fluorescent downlight illumination device

ABSTRACT

In various embodiments, a downlight illumination device is upgraded to an illumination device based on one or more light-emitting diodes (LEDs) via a retrofit kit that includes (i) a lighting module comprising one or more LEDs, (ii) a driver module comprising circuitry for receiving power from the power source and supplying compatible power to the one or more LEDs, (iii) a flexible conduit connecting the lighting module to the driver module and containing therewithin a plurality of wires electrically connecting the lighting module to the driver module, and (iv) an alignment bracket for attachment within the housing and configured to receive the lighting module.

RELATED APPLICATION

This application claims the benefit of and priority to U.S. ProvisionalPatent Application No. 61/972,801, filed Mar. 31, 2014, the entiredisclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

In various embodiments, the present invention relates to illuminationdevices, in particular illumination devices incorporating light-emittingdiodes.

BACKGROUND

One of the most common light fixtures is the recessed can downlight(RCD), which is an open-bottom can that contains a light bulb, mostcommonly an incandescent bulb or a fluorescent bulb. The fixture istypically connected to the power mains at 120 to 277 volts, 50/60 Hz.RCDs are generally installed during the construction of a buildingbefore the ceiling material (such as plaster or gypsum board) isapplied. Therefore, they are not easily removed or substantiallyreconfigured during their lifetime.

RCDs generally also accommodate light bulbs having various sizes,different overall dimensions (i.e., length, width, and diameter), andvaried light-distribution capabilities. For example, various bulbs havenarrow, medium, or wide (flood) distributions. Therefore, the internalfeatures of the RCD are constructed to accommodate many (if not all)different bulb types. Such features include mechanisms to adjust thevertical position of the bulb socket, as well as reflectors that channeland distribute the light. Because there are so many different lightbulbs and finishes, a very large number of trim rings and opticscombinations may be utilized in RCDs, in addition to the various spacersthat accommodate the bulbs. Thus a complex arrangement of parts isneeded for each RCD that is produced.

Because LEDs have very high efficiency (e.g., 100 lumens per wattcompared to 10-15 lumens per watt for incandescent or halogen lights)and a long lifetime (e.g., 10,000-100,000 hours), they are attractivefor virtually all lighting applications. However, even a dedicatedLED-based downlight would have the disadvantage of only being compatiblewith new construction (without a prohibitively costly overhaul of anentire lighting system and related infrastructure), and thus would beunavailable for retrofitting into the large installed base ofincandescent- or fluorescent-based RCDs. Moreover, because the LEDtechnology itself is rapidly changing, LED-based fixtures becomeobsolete as the LED technology, as well as the optics and coolingtechnology vital to performance, improve.

LED-based light bulbs represent a logical alternative. These productscontain electronics, optics and heat sinks all in a form factoridentical to that of the particular light bulb to be replaced. Suchdesigns may be quite difficult to achieve, however, and generallynecessitate strict control over power consumption in order to maintainlow enough operating temperatures to avoid thermally-induced prematurefailure. Hence, the light output of such LED light bulbs is typicallywell below that of the incandescent light bulbs they replace. Forexample, a PAR20 LED lamp from Lighting Sciences has a rated output of350 lumens while a conventional 50 watt PAR20 incandescent bulb haslight output in the range of 600-750 lumens. Furthermore, replacement ofthe light bulb product means discarding and replacing the entire suiteof electronics, optics, and heat sink—a costly and wasteful proposition.Moreover, the wide variety of existing RCDs would require an equallylarge number of different LED-based bulbs for one-to-one replacements,an expensive and complicated proposition.

Thus, there is a need for retrofit devices for RCDs based on LEDs thatare compatible with a wide range of differently sized and/or shaped RCDfixtures.

SUMMARY

Embodiments of the present invention advantageously enable retrofittingof a wide variety of different RCDs (e.g., RCDs incorporatingfluorescent bulbs) with a single “universal” LED-based retrofit kit thatis quickly and efficiently installable. Within the retrofit kit, the LEDlight sources and control electronics are modularized for ease ofassembly and installation. In addition, the retrofit kit may be utilizedsubstantially independent of the specific light bulb being replaced yetconforms to the volume and desired level of illumination of the existingRCD.

Embodiments of the invention typically include a discrete driver modulefeaturing circuitry for supplying power to and controlling the LED lightsource(s), as well as, in preferred embodiments, circuitry forcontrolling the LEDs based on sensed temperature (for example, thetemperature of the LEDs themselves or of one or more temperature sensorssuch as thermistors in close proximity to the LEDs). The driver moduleis electrically connected to a discrete lighting module featuring one ormore LEDs (for example, several LEDs arranged in a rectilinear array)via a flexible conduit that contains and protects one or more wirescarrying electrical signals between the two modules. Embodiments alsotypically include an alignment bracket that attaches within the RCDfixture (or a housing therein) and receives the lighting module duringinstallation. The alignment bracket preferably includes one or morefeatures configured to “self-align” the lighting module duringinstallation, thus enabling fast, accurate, and repeatable retrofittingof many RCDs in a building or other venue during a single installationsession.

In various embodiments of the invention, the lighting moduleincorporates one or more temperature sensors for sensing the temperatureof the LED(s) and/or the ambient temperature, and the driver moduleincorporates thermal-feedback circuitry for controlling power supply tothe LED(s) based on the sensed temperature. The lighting module alsotypically incorporates an integral or removable heat sink, and the heatsink and the alignment bracket typically have complementary featuresthat simplify the retrofit installation. The retrofit kit may alsoinclude a diffuser assembly configured to mechanically attach to thelighting module and diffuse the light emitted by the LEDs.

Although exemplary embodiments of the invention are described herein asretrofit kits and techniques for RCDs housing fluorescent light bulbs,embodiments of the invention are usable with other varieties ofconventional light bulbs, e.g., gas-discharge lamps, incandescent bulbs,halogen bulbs, high-intensity discharge bulbs, arc lamps, and the like.

In an aspect, embodiments of the invention feature a method of upgradinga downlight illumination device (e.g., a fluorescent, incandescent, orhalogen downlight illumination device) to an illumination device basedon one or more light-emitting diodes (LEDs). The downlight illuminationdevice to be upgraded includes or consists essentially of (i) a fixtureat least partially recessed into a ceiling, (ii) a reflective housingdisposed in the fixture, (iii) a socket for a light bulb (e.g., afluorescent light bulb, an incandescent light bulb, or a halogen lightbulb) disposed within the housing, and (iv) disposed outside of thehousing and electrically connected to the socket, a junction boxcomprising (a) one or more electrical connections to a power source and(b) a ballast for receiving power from the power source and supplyingcompatible power to the light bulb. A retrofit kit is provided. Theretrofit kit includes or consists essentially of (i) a lighting modulecomprising one or more LEDs, (ii) a driver module comprising circuitryfor receiving power from the power source and supplying compatible powerto the one or more LEDs, (iii) a flexible conduit (or other conduit orwired connection) connecting the lighting module to the driver moduleand containing therewithin a plurality of wires electrically connectingthe lighting module to the driver module, and (iv) an alignment bracketfor attachment within the housing and receiving the lighting module. Thesocket for the light bulb is removed from the housing. The ballast isdisconnected from the junction box. The electrical connection(s) of thejunction box are connected to the driver module. The driver module isaffixed to the fixture (e.g., outside of the housing and/or at leastpartially above the ceiling). The flexible conduit extends into thehousing such that the lighting module is positionable within thehousing. The alignment bracket is attached within the housing. Thelighting module is seated into the alignment bracket to retain thelighting module within the reflective housing, the lighting moduleremaining not directly electrically connected to the junction box duringoperation of the lighting module.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The lighting module may include orconsist essentially of (i) a substrate having a bottom surface uponwhich the one or more LEDs are disposed, and (ii) a heat sink disposedon a top surface of the substrate opposite the bottom surface. The heatsink may include or consist essentially of a thermally conductivematerial shaped to define (i) a plurality of fins extending away fromthe substrate, and (ii) integral with one or more of the fins, acylindrical mounting tube. The cylindrical mounting tube may extendalong substantially an entire lateral dimension (e.g., width, diameter,etc.) of the heat sink. The alignment bracket may include or consistessentially of one or more mounting clips configured to partiallyencircle the mounting tube of the heat sink. When the lighting module isseated into the alignment bracket, the mounting tube may be seatedwithin the one or more mounting clips. The flexible conduit may beconfigured for connection to the lighting module at one end of thecylindrical mounting tube. The end of the cylindrical mounting tube forconnection to the flexible conduit may be threaded. The retrofit kit mayinclude a connection means for securely attaching the flexible conduitto the end of the cylindrical mounting tube. The connection means mayinclude or consist essentially of one or more set screws and/or one ormore c-clamps.

The alignment bracket may include one or more vertical leaf springs (a)extending from each of a plurality of sides of the alignment bracket and(b) configured to align the heat sink with the alignment bracket whenthe lighting module is seated into the alignment bracket. When thelighting module is seated into the alignment bracket, each vertical leafspring may exert an alignment force on one or more fins of the heatsink. The alignment bracket may include one or more rotation leafsprings (a) extending from a bottom surface of the alignment bracket and(b) configured to exert a leveling force on the heat sink when thelighting module is seated into the alignment bracket. When the lightingmodule is seated into the alignment bracket, the rotation leaf springsmay maintain the substrate of the lighting module approximately parallelto the bottom surface of the alignment bracket. The alignment bracketmay include, associated with each of one or more of the rotation leafsprings, a rotation leaf spring stop positioned to contact a fin of theheat sink upon application of a predetermined amount of force on theassociated rotation leaf spring, which may thereby limit an amount offorce exertable on the associated rotation leaf spring.

The retrofit kit may include a diffuser assembly configured to (i)mechanically attach to the lighting module below the bottom surface ofthe substrate and/or (ii) diffuse light emitted by the one or more LEDstransmitted through the diffuser assembly. The diffuser assembly may bemechanically attached to the lighting module. The diffuser assembly maybe reversibly attachable to the lighting module. The heat sink maydefine a recessed groove in each of a plurality of sides of the heatsink. The heat sink may define a plurality of gaps between fins of theheat sink. The diffuser assembly may include one or more protrusionseach configured to engage the heat sink within one of the recessedgrooves and/or one of the gaps between fins. The diffuser assembly maydefine an opening sized to substantially accommodate the substrate ofthe lighting module. The diffuser assembly may include, opposite theopening, a diffusive surface for diffusing the light emitted by the oneor more LEDs. The diffuser assembly may include, extending from theopening to the diffusive surface, one or more reflective sidewalls fordistributing the light emitted by the one or more LEDs within aninterior volume of the diffuser assembly.

The retrofit kit may include a back-up power source. The retrofit kitmay include a second driver module, discrete from the driver module,comprising circuitry for receiving power from the back-up power sourceand supplying compatible power to the one or more LEDs, and a secondflexible conduit connecting the lighting module to the second drivermodule and containing therewithin a plurality of wires electricallyconnecting the lighting module to the second driver module. The back-uppower source and/or the second driver module may be affixed outside ofthe housing and/or at least partially above the ceiling. The secondflexible conduit may extend into the housing such that the lightingmodule is positionable within the housing. The back-up power source mayinclude or consist essentially of a micro inverter.

In another aspect, embodiments of the invention feature a retrofit kitfor upgrading a downlight illumination device (e.g., a fluorescent,incandescent, or halogen downlight illumination device) to anillumination device based on one or more light-emitting diodes (LEDs).The downlight illumination device to be upgraded includes or consistsessentially of (i) a fixture at least partially recessed into a ceiling,(ii) a reflective housing disposed in the fixture, (iii) a socket for alight bulb (e.g., a fluorescent light bulb, an incandescent light bulb,or a halogen light bulb) that may be disposed within the housing, and(iv) disposed outside of the housing and electrically connected to thesocket, a junction box comprising (a) one or more electrical connectionsto a power source and/or (b) a ballast for receiving power from thepower source and supplying compatible power to the light bulb. Theretrofit kit includes or consists essentially of a lighting modulecomprising one or more LEDs, a driver module comprising circuitry forreceiving power from the power source and supplying compatible power tothe one or more LEDs, a flexible conduit connecting the lighting moduleto the driver module and containing therewithin a plurality of wireselectrically connecting the lighting module to the driver module, and analignment bracket for attachment within the housing and configured toreceive the lighting module.

Embodiments of the invention may include one or more of the following inany of a variety of combinations. The lighting module may include orconsist essentially of (i) a substrate having a bottom surface uponwhich the one or more LEDs are disposed, and (ii) a heat sink disposedon a top surface of the substrate opposite the bottom surface. The heatsink may include or consist essentially of a thermally conductivematerial shaped to define (i) a plurality of fins extending away fromthe substrate, and (ii) integral with one or more of the fins, acylindrical mounting tube. The cylindrical mounting tube may extendalong substantially an entire lateral dimension (e.g., width, diameter,etc.) of the heat sink. The alignment bracket may include or consistessentially of one or more mounting clips configured to partiallyencircle the mounting tube of the heat sink. When the lighting module isseated into the alignment bracket, the mounting tube may be seatedwithin the one or more mounting clips. The flexible conduit may beconfigured for connection to the lighting module at one end of thecylindrical mounting tube. The end of the cylindrical mounting tubeconnected to the flexible conduit may be threaded. The retrofit kit mayinclude a connection means for securely attaching the flexible conduitto the end of the cylindrical mounting tube. The connection means mayinclude or consist essentially of one or more set screws and/or one ormore c-clamps.

The alignment bracket may include or consist essentially of one or morevertical leaf springs (i) extending from each of a plurality of sides ofthe alignment bracket and (ii) configured to align the heat sink withthe alignment bracket when the lighting module is seated into thealignment bracket. When the lighting module is seated into the alignmentbracket, each vertical leaf spring may exert an alignment force on oneor more fins of the heat sink. The alignment bracket may include orconsist essentially of a plurality of rotation leaf springs (i)extending from a bottom surface of the alignment bracket and (ii)configured to exert a leveling force on the heat sink when the lightingmodule is seated into the alignment bracket. When the lighting module isseated into the alignment bracket, the rotation leaf springs maymaintain the substrate of the lighting module approximately parallel tothe bottom surface of the alignment bracket. The alignment bracket mayinclude, associated with each of one or more of the rotation leafsprings, a rotation leaf spring stop positioned to contact a fin of theheat sink upon application of a predetermined amount of force on theassociated rotation leaf spring, which may limit an amount of forceexertable on the associated rotation leaf spring.

The retrofit kit may include a diffuser assembly configured to (i)mechanically attach to the lighting module below the bottom surface ofthe substrate and/or (ii) diffuse light emitted by the one or more LEDstransmitted through the diffuser assembly. The diffuser assembly may bereversibly attachable to the lighting module. The heat sink may define arecessed groove in each of a plurality of sides of the heat sink. Theheat sink may define a plurality of gaps between fins of the heat sink.The diffuser assembly may include one or more protrusions eachconfigured to engage the heat sink within one of the recessed groovesand/or one of the gaps between fins. The diffuser assembly may define anopening sized to substantially accommodate the substrate of the lightingmodule. The diffuser assembly may include, opposite the opening, adiffusive surface for diffusing the light emitted by the one or moreLEDs. The diffuser assembly may include, extending from the opening tothe diffusive surface, one or more reflective sidewalls for distributingthe light emitted by the one or more LEDs within an interior volume ofthe diffuser assembly. The retrofit kit may include a back-up powersource. The retrofit kit may include a second driver module, discretefrom the driver module, comprising circuitry for receiving power fromthe back-up power source and supplying compatible power to the one ormore LEDs, and a second flexible conduit connecting the lighting moduleto the second driver module and containing therewithin a plurality ofwires electrically connecting the lighting module to the second drivermodule. The back-up power source may include or consist essentially of amicro inverter.

These and other features of selected embodiments disclosed herein, alongwith their respective possible advantages, will become more apparentthrough reference to the following description, the accompanyingdrawings, and the claims. Furthermore, it is to be understood that thefeatures of the various embodiments described herein are not mutuallyexclusive and can exist in various combinations and permutations. Asused herein unless otherwise indicated, the terms “substantially” and“approximately” mean ±10%, and, in some embodiments, ±5%. The term“consists essentially of” means excluding other materials thatcontribute to function, unless otherwise defined herein. Nonetheless,such other materials may be present, collectively or individually, intrace amounts.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIG. 1 is an exploded view of a retrofit kit in accordance withembodiments of the invention;

FIG. 2A is an exploded view of portions of a retrofit kit in accordancewith embodiments of the invention;

FIGS. 2B, 2C, and 2D are views of portions of a retrofit kitinterfitting together in accordance with embodiments of the invention;

FIG. 2E is a magnified view of a portion of the retrofit kit depicted inFIG. 2D;

FIG. 3A is a view of portions of a retrofit kit interfitting together inaccordance with embodiments of the invention;

FIG. 3B is a magnified view of a portion of the retrofit kit depicted inFIG. 3A;

FIG. 3C is a bottom view of portions of a retrofit kit in accordancewith embodiments of the invention;

FIG. 4 is a flowchart of a method of installation of a retrofit kit inaccordance with embodiments of the invention;

FIGS. 5A and 5B are views of a retrofit kit installed in a fixture inaccordance with embodiments of the invention;

FIG. 6 is a view of a retrofit kit in accordance with embodiments of theinvention;

FIG. 7A is a view of an interconnection scheme for portions of aretrofit kit in accordance with embodiments of the invention; and

FIG. 7B is a view of the portions of the retrofit kit shown in FIG. 7Aafter interconnection.

DETAILED DESCRIPTION

FIG. 1 depicts a retrofit kit 100 in accordance with embodiments of thepresent invention. As shown, the retrofit kit 100 features a lightingmodule 105 containing one or more LEDs 110 on its bottom surface (seeFIG. 3C) and a heat sink 115 on its top surface, as well as a drivermodule 120 that houses circuitry for receiving power from the powersource powering the RCD to be upgraded (e.g., the AC mains) andtransforming such electrical power into a form suitable to drive theLEDs 110 (e.g., DC current). The lighting module 105 may feature asubstrate upon which the LEDs 110 are disposed, and the LEDs 110 may bepackaged (e.g., with integrated optics and/or encapsulation) and/orsubstantially unpackaged (e.g., bare dies), and may individually and/orcollectively emit any of a variety of colors of light, including whitelight. The heat sink 115 on the opposite side of the substrate typicallyfeatures, as shown, a large surface area formed by multiple elongatedand spaced-apart fins. As described in more detail below, the heat sink115 may also incorporate shaped features that facilitate alignment andinstallation of the lighting module 105 within the RCD fixture.

The driver module 120 may include dimmers, transformers, rectifiers, orballasts suitable for operation with the LEDs 110, as understood bythose of skill in the art, and such components (and/or any othercircuitry) of the driver module 120 may be disposed on a printed circuitboard. In preferred embodiments, the driver module 120 also provides forthermal feedback (or “foldback”) to protect the LEDs 110, as describedin, e.g., U.S. Pat. No. 7,777,430, filed Oct. 30, 2007, U.S. Pat. No.8,358,085 (the '085 patent), filed Jan. 6, 2010, and U.S. PatentApplication Publication Nos. 2011/0121760, filed Nov. 17, 2010, and2012/0299481, filed May 25, 2012, the entire disclosures of which areincorporated by reference herein. For example, the driver module 120 mayutilize the temperature sensed at the lighting module 105 to provideover-temperature protection (i.e., reduction in the power supplied tothe LEDs 110). The driver module 120 may even incorporate featuresdescribed in the '085 patent to enable two-wire temperature sensing and,thus, the maintaining of the LEDs 110 within a safe operatingtemperature range. The driver module 120 also typically provideselectrical isolation from the mains power, and is self-contained and mayincorporate other features such as one or more fuses.

As shown in FIG. 1, the lighting module 105 and the driver module 120may be connected by a flexible conduit 125 that houses the one or more(e.g., four, or, as shown in FIGS. 7A and 7B, three) wires that supplypower to the LEDs 110 and transmit sensed temperature information andthermal-foldback control signals. The wires may be strain-relieved andare protected from environmental or mechanical damage by the flexibleconduit 125. As shown, the flexible conduit 125 may extend between, andbe threadedly engaged to, the driver module 120 and one end of acylindrical mounting tube 130 attached to or defined by a portion of theheat sink 115 of the lighting module 105. The mounting tube 130 mayextend along substantially along an entire dimension (e.g., width) ofthe heat sink 105. In other embodiments of the present invention, theflexible conduit 125 engages with the cylindrical mounting tube 130 viaa pivotable and/or rotatable conduit connector as described in U.S.Provisional Patent Application No. 62/097,822, filed on Dec. 30, 2014,the entire disclosure of which is incorporated by reference herein.

The retrofit kit 100 also preferably includes an alignment bracket 135that attaches within the RCD fixture and receives the lighting module105 during the retrofit installation. As described in more detail below,the alignment bracket 135 preferably includes one or more featuresconfigured to “self-align” the lighting module 105 during installation.The retrofit kit 100 may also include a diffuser assembly 140 configuredto mechanically attach to the lighting module 105 and diffuse the lightemitted by the LEDs 110. The diffuser assembly 140 may be removablyattachable to the lighting module 105. The diffuser assembly 140 mayhave an opening sized to substantially accommodate the illuminationsurface (or “substrate”) of the lighting module 105, and may have,opposite the opening, a diffusive surface or removable diffusive platefor diffusing the light emitted by the LEDs 110 (so that, e.g.,individual points of light corresponding to the LEDs 110 are notdiscernable by an observer). The diffuser assembly 140 may define aninterior volume (or “mixing chamber”) in which the LED light isdistributed via, for example, reflection from one or more reflectivesidewalls of the diffuser assembly 140.

FIGS. 2A-2E depict various features of the alignment bracket 135 and theheat sink 115 of the lighting module 105 configured to facilitate rapidand repeatable installation of the retrofit kit 100 within an RCDfixture. As shown in FIG. 2A, the alignment bracket 135 may include oneor more mounting clips 200 (or “mounting c-clips” or “mounting c-clipleaf springs”) that are configured to receive and partially encircle themounting tube 130 of the heat sink 115, such that, when the mountingtube 130 seats into the alignment bracket 135 (see FIG. 2D), themounting tube 130 is seated within the mounting clips 200. As shown inFIG. 2C, as the heat sink 115 is pressed upwards when the lightingmodule 105 is seated into the alignment bracket 135, the mounting clips200 receive the cylindrical mounting tube 130 and thus center the heatsink 115 within the mounting bracket 135 with a centering and/orleveling force (represented by arrows 235).

As also shown in FIG. 2A, the alignment bracket 135 also may feature oneor more vertical leaf springs 210 (or “front-to-back alignment leafsprings”) extending from each of multiple sides of the alignment bracket135. The vertical leaf springs 210 are configured to align the heat sink115 with the alignment bracket 135 when the lighting module 105 isseated into the alignment bracket 135. As shown in FIG. 2B, when thelighting module 105 is seated into the alignment bracket 135 (via, e.g.,force exerted by the installer, represented by arrow 215), each verticalleaf spring 210 exerts an alignment (or “centering”) force (representedby arrows 220) on one or more fins of the heat sink 115.

The alignment bracket 135 may also include multiple rotation leafsprings 225 (or “rotation alignment leaf springs”) that extend from thebottom surface of the alignment bracket 135 and are configured to exerta leveling force on the heat sink 115 when the lighting module 105 isseated into the alignment bracket 135. As shown in FIGS. 2D and 2E, whenthe lighting module 105 is seated into the alignment bracket, therotation leaf springs exert leveling force on the heat sink so as tomaintain the lighting module 105 (and/or features thereof) approximatelyparallel to the bottom surface of the alignment bracket 135. Forexample, rotation leaf springs 225 positioned on opposite sides of thebottom surface of the alignment bracket 135 may impose substantiallyequal torque (represented as arrows 230) when the mounting tube 130 isseated within the mounting clips 200, thereby “leveling” the lightingmodule 105 within the alignment bracket 135 and within the RCD fixture.As also shown in FIGS. 2A, 2D, and 2E, each rotation leaf spring 225 maybe associated with a rotation leaf spring stop 240 positioned to contacta portion (e.g., a fin) of the heat sink 115 upon application of apredetermined amount of force on the associated rotation leaf spring225. In this manner, the rotation leaf spring stops 240 limit the amountof force that may be exerted on the rotation leaf springs 225 and thusprevent the rotation leaf springs 225 from becoming over-stressed orbreaking.

FIGS. 3A-3C depict the diffuser assembly 140 of the retrofit kit 100 ingreater detail. As shown, the diffuser assembly 140 may be reversiblyattachable to the lighting module 105 (e.g., to the heat sink 115 of thelighting module 105) via one or more protrusions 300 each configured toengage the lighting module 105 via, e.g., a recessed groove 305 in theheat sink 115 or a gap 310 between fins of the heat sink 115, as shownin FIGS. 3A and 3B. The protrusions 300 may be rounded, e.g., shaped as,for example, hemispheres or partial spheres. As mentioned above, and asshown in FIG. 3C, the diffuser assembly 140 may feature an at leastpartially enclosed mixing chamber 315 in which the light emitted by theLEDs 110 is mixed, combined, and substantially equally distributed andemitted through the diffusive surface of the diffuser assembly 140 (notshown for clarity). The interior sidewalls 320 of the mixing chamber 315are thus preferably reflective and/or angled with respect to the surfacenormal of the emission surface of the lighting module 105 on which theLEDs 110 are disposed. For example, the interior sidewalls 320 may becoated with white paint or be composed of a suitably reflectivematerial. Preferably, the individual LEDs 110 of the lighting module 105are not visible to an observer once the retrofit kit 100 is installeddue to the presence of the diffuser assembly 135 and its diffusivebottom surface.

Referring to FIGS. 4, 5A, and 5B, in accordance with various embodimentsof the invention, the retrofit kit 100 is utilized to upgrade an RCD(e.g., a fluorescent light-based RCD). The RCD to be upgraded mayfeature a fixture 500 at least partially recessed into a ceiling, areflective housing 505 disposed in the fixture 500, a socket for aconventional (e.g., fluorescent) light bulb within the housing 505, anda junction box 510 (or “j-box”). The junction box 510 is typicallydisposed outside of the housing 505 and electrically connected to thesocket via, e.g., one or more wires. The junction box 510 also typicallyincludes electrical connections to the power source supplying power tothe RCD (e.g., the AC mains), and the junction box 510 may also includea ballast for receiving power from the power source and supplyingcompatible power to the conventional light bulb.

As shown in FIG. 4, in step 405 of a method 400, power to the fixture500 is shut off, e.g., at the circuit breaker panel for the fixture 500,and the retrofit kit 100 is provided. Then, in a step 410, theconventional bulb(s) (if present) and the socket for the conventionalbulb are typically removed from the reflective housing 505, and in astep 415, the ballast (if present) is disconnected from the junction box510. In a step 420, the electrical connections of the junction box 510are connected to the driver module 120, and in a step 425, the drivermodule 120 is affixed to the fixture 500 (and/or to the junction box510) outside of the housing 505 (and preferably, above the ceiling). Atthis point, the flexible conduit 125 typically extends into the housing505 such that the lighting module 105 is adjustably positionable withinthe housing 505 (as shown in FIG. 5A). In a step 430, the alignmentbracket 135 is then attached within the housing 505, for example, on theinterior of the top surface of the housing 505. Finally, in a step 435,the lighting module 105 is seated into the alignment bracket 135 toretain the lighting module 105 within the reflective housing 505. Thediffuser assembly 140 may also be attached to (e.g., snapped into placeon) the lighting module 105 at any point in the installation procedure,or the diffuser assembly 140 may be pre-installed on the lighting module105. Power to the fixture 500 is then restored, and the LEDs 110 of thelighting module 105 supply the illumination previously supplied by theconventional light bulb(s).

FIGS. 5A and 5B depict the retrofit kit 100 installed within the RCDfixture 500. As shown, the lighting module 105 remains electricallyconnected only to the driver module 120 (and thus only indirectlyconnected to the junction box 510), and thus not directly electricallyconnected to the junction box 510, during subsequent operation of thelighting module 105. This arrangement facilitates rapid and easyinstallation of the retrofit kit 100, including the electricalconnection of the retrofit kit 100 to the RCD power source. In addition,the driver module 120 is mounted and present outside of the RCD housing505, facilitating the retrofitting of even low-profile or small RCDfixtures which need not accommodate the driver module 120 in addition tothe lighting module 105.

In various embodiments of the present invention and as shown in FIG. 6,the retrofit kit 100 may also incorporate a back-up source of power 600,such as one or more batteries. For example, the retrofit kit 100 mayincorporate two different driver modules 120-1, 120-2 each connected tothe lighting module 105 via a separate flexible conduit 125 (shown as125-1, 125-2 in FIG. 6). One driver module 120-1 may be connected to theAC mains, as detailed above, and the other driver module 120-2 may beconnected to the back-up source of power 600. Thus, the retrofit kit 100may include the back-up source of power 600, which in some embodimentsincludes or consists essentially of a micro inverter that includes oneor more batteries (e.g., rechargeable batteries), such as one of the ELISERIES Emergency Lighting Inverters (e.g., the ELI-S-20) available fromPhilips Bodine of Collierville, Tenn. The micro inverter (or otherback-up source of power 600) provides a back-up source of power, via thesecond driver module 120-2, to the lighting module 105, thus allowingthe lighting module 105 to function even in the event of loss of powerfrom the AC mains. The micro inverter may be connected to the seconddriver module 120-2 (via, e.g., flexible conduit 125-2), and both themicro inverter and the second driver module 120-2 may be positioned inor near the fixture 500 but outside of the housing 505.

As also shown in FIG. 6, retrofit kit 100 may include a threadedstand-off 605. In some embodiments, the housing 505 is affixed to thefixture 500 via a fastener such as a screw and wingnut. When thealignment bracket 135 is seated into the housing 505, it is typicallyattached to the housing 505 via the same fastener, and the fastener(e.g., the screw) may have a length insufficient to affix both thehousing 505 and the alignment bracket 135 within the fixture 500. Insuch cases, the stand-off 605 may be attached to the fastener tolengthen the fastener and facilitate the installation of the alignmentbracket 135.

As mentioned above and depicted in FIGS. 1 and 2A, the flexible conduit125 may extend between, and be threadedly engaged to, the driver module120 and one end of the cylindrical mounting tube 130. Thus, at least oneend of the cylindrical mounting tube 130 may be threaded for engagementwith the flexible conduit 125. FIGS. 7A and 7B depict an alternativeengagement technique for the flexible conduit 125. As shown, the wires700 extending through the flexible conduit 125 from the driver module120 may be attached to wires 705 extending from the lighting module 105and through the cylindrical mounting tube 130 via, e.g., a connectorplug that includes or consists of connector plug ends 710, 715. The endof the flexible conduit 125 configured for attachment to the mountingtube 130 may also have an insulating bushing 720 therein or thereon toprevent wire shorts. Once the wires 700, 705 are connected, the flexibleconduit 125 may be mechanically connected to the mounting tube 130 via aset screw 725 that extends through the wall of the mounting tube 130 andengages with the flexible conduit 125 (e.g., between cylindricalprotrusions thereof), as shown in FIG. 7B. Alternatively or in addition,a c-clamp, a spring clamp, a band clamp, or a clamping collar (e.g., aone-piece clamping collar or a two-piece clamping collar) may beutilized to mechanically connect the flexible conduit 125 to themounting tube 130.

The terms and expressions employed herein are used as terms ofdescription and not of limitation, and there is no intention, in the useof such terms and expressions, of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theinvention claimed.

What is claimed is:
 1. A method of upgrading, to an illumination devicebased on one or more light-emitting diodes (LEDs), a fluorescentdownlight illumination device comprising (i) a fixture at leastpartially recessed into a ceiling, (ii) a reflective housing disposed inthe fixture, (iii) a socket for a fluorescent light bulb disposed withinthe housing, and (iv) disposed outside of the housing and electricallyconnected to the socket, a junction box comprising (a) electricalconnections to a power source and (b) a ballast for receiving power fromthe power source and supplying compatible power to the fluorescent lightbulb, the method comprising: providing a retrofit kit comprising (i) alighting module comprising: (a) one or more LEDs, (b) a substrate havinga bottom surface upon which the one or more LEDs are disposed, and (c) aheat sink disposed on a top surface of the substrate opposite the bottomsurface, (ii) a driver module comprising circuitry for receiving powerfrom the power source and supplying compatible power to the one or moreLEDs, (iii) a flexible conduit connecting the lighting module to thedriver module and containing therewithin a plurality of wireselectrically connecting the lighting module to the driver module, and(iv) an alignment bracket for attachment within the housing andreceiving the lighting module, wherein the heat sink further comprises athermally conductive material shaped to define (a) a plurality of finsextending away from the substrate, and (b) integral with one or more ofthe fins, a cylindrical mounting tube; removing the socket for thefluorescent light bulb from the housing; disconnecting the ballast fromthe junction box; connecting the electrical connections of the junctionbox to the driver module; affixing the driver module to the fixtureoutside of the housing and above the ceiling, the flexible conduitextending into the housing such that the lighting module is positionablewithin the housing; attaching the alignment bracket within the housing;and seating the lighting module into the alignment bracket to retain thelighting module within the reflective housing, the lighting moduleremaining not directly electrically connected to the junction box duringoperation of the lighting module.
 2. The method of claim 1, wherein thecylindrical mounting tube extends along substantially an entire width ofthe heat sink.
 3. The method of claim 1, wherein (i) the alignmentbracket comprises one or more mounting clips configured to partiallyencircle the mounting tube of the heat sink, and (ii) when the lightingmodule is seated into the alignment bracket, the mounting tube is seatedwithin the one or more mounting clips.
 4. The method of claim 1, whereinthe flexible conduit is configured for connection to the lighting moduleat one end of the cylindrical mounting tube.
 5. The method of claim 4,wherein the end of the cylindrical mounting tube connected to theflexible conduit is threaded.
 6. The method of claim 4, wherein theretrofit kit comprises a connection means for securely attaching theflexible conduit to the end of the cylindrical mounting tube.
 7. Themethod of claim 6, wherein the connection means comprises at least oneof a set screw or a c-clamp.
 8. The method of claim 1, wherein thealignment bracket comprises one or more vertical leaf springs (a)extending from each of a plurality of sides of the alignment bracket and(b) configured to align the heat sink with the alignment bracket whenthe lighting module is seated into the alignment bracket, whereby whenthe lighting module is seated into the alignment bracket, each verticalleaf spring exerts an alignment force on one or more fins of the heatsink.
 9. The method of claim 1, wherein the alignment bracket comprisesa plurality of rotation leaf springs (a) extending from a bottom surfaceof the alignment bracket and (b) configured to exert a leveling force onthe heat sink when the lighting module is seated into the alignmentbracket, whereby when the lighting module is seated into the alignmentbracket, the rotation leaf springs maintain the substrate of thelighting module approximately parallel to the bottom surface of thealignment bracket.
 10. The method of claim 9, wherein the alignmentbracket comprises, associated with each of one or more of the rotationleaf springs, a rotation leaf spring stop positioned to contact a fin ofthe heat sink upon application of a predetermined amount of force on theassociated rotation leaf spring, thereby limiting an amount of forceexertable on the associated rotation leaf spring.
 11. The method ofclaim 1, wherein the retrofit kit comprises a diffuser assemblyconfigured to (i) mechanically attach to the lighting module below thebottom surface of the substrate and (ii) diffuse light emitted by theone or more LEDs transmitted through the diffuser assembly, and furthercomprising mechanically attaching the diffuser assembly to the lightingmodule.
 12. The method of claim 11, wherein the diffuser assembly isreversibly attachable to the lighting module.
 13. The method of claim11, wherein (i) the heat sink defines a recessed groove in each of aplurality of sides of the heat sink, and (ii) the diffuser assemblycomprises a plurality of protrusions each configured to engage the heatsink within one of the recessed grooves.
 14. The method of claim 11,wherein the diffuser assembly (i) defines an opening sized tosubstantially accommodate the substrate of the lighting module, (ii)comprises, opposite the opening, a diffusive surface for diffusing thelight emitted by the one or more LEDs, and (iii) comprises, extendingfrom the opening to the diffusive surface, one or more reflectivesidewalls for distributing the light emitted by the one or more LEDswithin an interior volume of the diffuser assembly.
 15. The method ofclaim 1, wherein the retrofit kit comprises (i) a back-up power source,(ii) a second driver module, discrete from the driver module, comprisingcircuitry for receiving power from the back-up power source andsupplying compatible power to the one or more LEDs, and (iii) a secondflexible conduit connecting the lighting module to the second drivermodule and containing therewithin a plurality of wires electricallyconnecting the lighting module to the second driver module.
 16. Themethod of claim 15, further comprising affixing the back-up power sourceand the second driver module to the fixture outside of the housing andabove the ceiling, the second flexible conduit extending into thehousing such that the lighting module is positionable within thehousing.
 17. The method of claim 15, wherein the back-up power sourcecomprises a micro inverter.
 18. A retrofit kit for upgrading, to anillumination device based on one or more light-emitting diodes (LEDs), adownlight illumination device comprising (i) a fixture at leastpartially recessed into a ceiling, (ii) a reflective housing disposed inthe fixture, (iii) a socket for a light bulb, and (iv) disposed outsideof the housing and electrically connected to the socket, a junction boxcomprising electrical connections to a power source, the retrofit kitcomprising: a lighting module comprising (a) one or more LEDs disposedon a substrate having a top and bottom surface and (b) a heat sinkdisposed on the top surface of the substrate, wherein the heat sinkcomprises a thermally conductive material shaped to define (1) aplurality of fins extending away from the substrate, and (2) acylindrical mounting tube, integral with one or more of the fins; adriver module comprising circuitry for receiving power from the powersource and supplying compatible power to the one or more LEDs; aflexible conduit connecting the lighting module to the driver module andcontaining therewithin a plurality of wires electrically connecting thelighting module to the driver module; and an alignment bracket forattachment within the housing and configured to receive the lightingmodule.
 19. The retrofit kit of claim 18, wherein the cylindricalmounting tube extends along substantially an entire width of the heatsink.
 20. The retrofit kit of claim 18, wherein the alignment bracketcomprises one or more mounting clips configured to partially encirclethe mounting tube of the heat sink, whereby, when the lighting module isseated into the alignment bracket, the mounting tube is seated withinthe one or more mounting clips.
 21. The retrofit kit of claim 18,wherein the flexible conduit is configured for connection to thelighting module at one end of the cylindrical mounting tube.
 22. Theretrofit kit of claim 21, wherein the end of the cylindrical mountingtube connected to the flexible conduit is threaded.
 23. The retrofit kitof claim 21, further comprising a connection means for securelyattaching the flexible conduit to the end of the cylindrical mountingtube.
 24. The retrofit kit of claim 23, wherein the connection meanscomprises at least one of a set screw or a c-clamp.
 25. The retrofit kitof claim 18, wherein the alignment bracket comprises one or morevertical leaf springs (i) extending from each of a plurality of sides ofthe alignment bracket and (ii) configured to align the heat sink withthe alignment bracket when the lighting module is seated into thealignment bracket, whereby, when the lighting module is seated into thealignment bracket, each vertical leaf spring exerts an alignment forceon one or more fins of the heat sink.
 26. The retrofit kit of claim 25,wherein the alignment bracket comprises a plurality of rotation leafsprings (i) extending from a bottom surface of the alignment bracket and(ii) configured to exert a leveling force on the heat sink when thelighting module is seated into the alignment bracket, whereby, when thelighting module is seated into the alignment bracket, the rotation leafsprings maintain the substrate of the lighting module approximatelyparallel to the bottom surface of the alignment bracket.
 27. Theretrofit kit of claim 26, wherein the alignment bracket comprises,associated with each of one or more of the rotation leaf springs, arotation leaf spring stop positioned to contact a fin of the heat sinkupon application of a predetermined amount of force on the associatedrotation leaf spring, thereby limiting an amount of force exertable onthe associated rotation leaf spring.
 28. The retrofit kit of claim 18,further comprising a diffuser assembly configured to (i) mechanicallyattach to the lighting module below the bottom surface of the substrateand (ii) diffuse light emitted by the one or more LEDs transmittedthrough the diffuser assembly.
 29. The retrofit kit of claim 28, whereinthe diffuser assembly is reversibly attachable to the lighting module.30. The retrofit kit of claim 28, wherein (i) the heat sink defines arecessed groove in each of a plurality of sides of the heat sink, and(ii) the diffuser assembly comprises a plurality of protrusions eachconfigured to engage the heat sink within one of the recessed grooves.31. The retrofit kit of claim 28, wherein the diffuser assembly (i)defines an opening sized to substantially accommodate the substrate ofthe lighting module, (ii) comprises, opposite the opening, a diffusivesurface for diffusing the light emitted by the one or more LEDs, and(iii) comprises, extending from the opening to the diffusive surface,one or more reflective sidewalls for distributing the light emitted bythe one or more LEDs within an interior volume of the diffuser assembly.32. The retrofit kit of claim 18, further comprising (i) a back-up powersource, (ii) a second driver module, discrete from the driver module,comprising circuitry for receiving power from the back-up power sourceand supplying compatible power to the one or more LEDs, and (iii) asecond flexible conduit connecting the lighting module to the seconddriver module and containing therewithin a plurality of wireselectrically connecting the lighting module to the second driver module.33. The retrofit kit of claim 32, wherein the back-up power sourcecomprises a micro inverter.